Windows 11 users on some Samsung PCs lose C: drive access after February updates
Mar 14th 2026
Microsoft is probing a Windows 11 issue after February 2026 security updates that causes C:\ access denied errors on some Samsung laptops, blocking apps and administrative tasks.
- Microsoft is investigating reports that February 2026 Windows 11 security updates cause loss of access to the C:\ drive on some Samsung laptops.
- Affected systems run Windows 11 versions 25H2 and 24H2 and include Samsung Galaxy Book 4 and other Samsung consumer devices, with many reports from Brazil, Portugal, South Korea and India.
- Users may see the error "C:\ is not accessible - Access denied", which prevents opening files and launching apps including Outlook, Office, web browsers, system utilities and Quick Assist.
- The issue can also block privilege elevation, uninstalling updates, and access to system logs, complicating recovery.
- Microsoft says it is working with Samsung and points to the Samsung Share app as a possible factor but has not confirmed a root cause.
- There is no official workaround yet and a user-posted fix that changes C:\ ownership to Everyone weakens system security and is not recommended.